Create per-call translation options by negotiating an Accept-Language header.
Unusable input produces an unmatched result (locale: null, matchType: "none"),
so the runtime uses its configured fallback while preserving that diagnostic.
The raw header is limited to 4,096 UTF-16 code units and the parsed list to
32 ranges, including IANA equivalents. Oversized lists are rejected as a whole;
no preferences are retained in the unmatched result.
Create per-call translation options by negotiating an
Accept-Languageheader. Unusable input produces an unmatched result (locale: null,matchType: "none"), so the runtime uses its configured fallback while preserving that diagnostic.The raw header is limited to 4,096 UTF-16 code units and the parsed list to 32 ranges, including IANA equivalents. Oversized lists are rejected as a whole; no preferences are retained in the unmatched result.